If you want to play LSPDFR, Scripthook V is not a requirement.
Scripthook V is a requirement for using non-RPH scripts such as ELS or SimpleTrainer.
To play LSPDFR whilst waiting for a ScripthookV update, or to remove Scripthook V, follow these instructions:
In Windows Explorer, go to your GTA V folder. Usually 'C:\Program Files\Rockstar Games\Grand Theft Auto V' for RGSC/Retail version and something like 'c:\program files (x86)\Steam\SteamApps\common\Grand Theft Auto V' for Steam.
Delete ScriptHookV.dll.
Your ScriptHookV mods won't work, so this method should only be used whilst waiting for a Scripthook V update because you have no backup available or some other scenario.